1. Field of the Invention
The present invention relates to an end structure for a high-frequency coaxial connector required to be electro-magnetically insulated from the outside and also relates to a method of treating the end of the hight-frequency coaxial connector.
2. Description of the Related Art
Japanese Utility Model Publication (kokai) No. 4-52371 discloses a high-frequency coaxial connector. FIG. 1 is a perspective view of the above coaxial connector and FIG. 2 is a sectional view of the connector.
As shown in FIGS. 1 and 2, a shield wire 1 is provided with a core line 1a, an insulating inner rind 1b, and a braided wire 1c all of which are exposed from an insulating outer rind 1d at the end of the wire 1. A rod-shaped terminal 2 is press-fitted to the exposed core 1a. A shield member 3 includes a terminal retainer 3a in the form of a rectangular box, and a pair of shield pieces 3b, 3c connected with the terminal retainer 3a through a hinge 4. A terminal insertion hole 5 is formed in the terminal retainer 3a. The terminal 2 is adapted so as to be connected with the shield wire 1 and inserted into the terminal inserting hole 5.
The pair of shield pieces 3b, 3c are formed so as to be displaceable from an opening position for opening their abutting faces to the closing position for abutting the abutting faces against each other. Each of the shield pieces 3b, 3c is provided, on an end face thereof, with a contact face 6 for contact with the braided wire 1c of the shield wire 1.
With the above-mentioned constitution, the terminal 2 connected to the shield wire 1 is inserted into the shield member 3 through an opening between the shield pieces 3b, 3c and further inserted into the terminal insertion hole 5. Next, the pair of shield pieces 3b, 3c are closed, so that the abutting faces abut on each outer while the respective contact faces 6 come in contact with the braided wire 1c. Consequently, the terminal 2 is electrically connected with the shield member 3, while the terminal 2 and the exposed tore 1a are magnetically insulated from the outside by the shield member 3.
Japanese Patent Publication (kokai) No. 7-22107 discloses a high-frequency coaxial connector. FIG. 3 is a sectional view of the above coaxial connector before assembling an insulating member and FIG. 4 is a sectional view of the connector after assembling the member.
As shown in FIGS. 3 and 4, a shield wire 1xe2x80x2 is provided with the core line 1a, the insulating inner rind 1b, and the braided wire 1c all of which are exposed from the insulating outer rind 1d at the end of the wire 1. An inner terminal 2xe2x80x2 is electrically connected to the exposed core 1a. A shield terminal 7 includes a retainer 7a in the form of a rectangular cylinder, a xe2x80x9cbraided wirexe2x80x9d press-fitting part 7b extended from the rear end of the retainer 7a and a xe2x80x9cinsulating rindxe2x80x9d press-fitting part 7c succeeding to the part 7b. In the rectangular cylindrical retainer 7a, an inner housing 8 is arranged to accommodate the terminal and provided with a groove part 8a. Respective openings 7d, 8d are formed on the retainer 7a and the top face of the inner housing 8, respectively. The openings 7d, 8d are adapted so as to be covered with a covering member 9.
With the above-mentioned constitution, the inner terminal 2xe2x80x2 connected to the shield wire 1xe2x80x2 is inserted into the groove part a of the inner housing 8 through the respective opening 7d of the terminal 7 and the opening 8d of the inner housing 8. Next, the covering member 9 is attached to the inner housing 8 to close the opening 8d. Further, by crimping the press-fitting parts 7b, 7c, the press-fitting part 3b is pressure-connected to the braided wire 1c while the press-fitting part 7c is pressure-connected to the insulating outer rind 1d. In this manner, the inner terminal 2xe2x80x2 is electrically connected with the shield terminal 7, while the terminal 2xe2x80x2 and the exposed core Ic are magnetically insulated from the outside by the shield terminal 7, similar to the previously-mentioned prior art.
In the former prior art, however, there is a problem of incomplete assembly with the result being that the pair of shield pieces 3b, 3c are easily deformed by an external force in a direction to separate the pieces 3b, 3c from each other because the contact between the respective faces 6 and the braided wire 1c of the shield wire 1 is attained owing to the plastic deformation of the shield pieces 3b, 3c of the shield member 3. In detail, if the shield pieces 3b, 3e are subjected to an external force to open them, then there is easily produced a clearance between the opposing faces of the shield pieces 3b, 3c, so that a electrical contact between the faces 6 and the braided wire 14 becomes incomplete, thereby deteriorating the shielding capability.
In the latter prior art, conversely, the assembling condition is stable owing to the arrangement where the shield terminal 7 is connected to the shield wire 1xe2x80x2 through the press-fitting part 3b for the braided wire 1c and the press-fitting part 7c for the insulating out rind 1d. However, since the rear opening d. of the shield terminal 7 and the rear opening d. of the inner housing 8 are respectively closed by the covering member 9, the number of components is so large that the number of assembly steps is increased, causing an increase in manufacturing costs, Additionally noted, unless the opening d., d. are closed by the covering opening 9, the shielding capability would be deteriorated in a high-frequency band range, particularly.
Under such a circumstance, it is therefore an object of the present invention to provide an end structure for a coaxial connector which is complete in its assembling condition and capable of maintaining the shielding capability without increasing the number of components and assembling steps.
Further, it is another object to provide a method of treating the end of the coaxial connector.
The objects of the present invention described above can be accomplished by an end structure for a coaxial connector comprising:
a shield wire having a conductive core, an insulating inner rind covering the core, a conductive braided wire covering the insulating inner rind and an insulating outer rind covering the braided wire, the shield wire being partially peeled at an end thereof so as to expose the core, the insulating inner rind and the braided wire;
an inner terminal to be press-fitted to the exposed core for electrical connection;
an inner housing made of insulating material, the inner housing having an inner terminal accommodating part formed for accommodating the inner terminal inserted thereinto;
a shield terminal to be assembled to the inner terminal and the exposed braided wire through the inner housing so as to attain an electrical connection with the braided wire, the shield terminal being configured to be connectable with the exposed braided wire by the shield terminal""s press-fitting so as to cover at least the inner terminal and the exposed insulating inner rind;
wherein the shield terminal includes:
a bottom part;
a pair of half-box parts formed to stand on both sides of the bottom part integrally and allow of plastic deformation due to press-fitting to their closing position where respective opposing end faces of the half-box parts butt each other; and
a pair of press-fitting parts formed to stand on both sides of the bottom part and also configured to be connectable with the exposed braided wire by the press-fitting parts press-fitting;
whereby the inner housing, the inner terminal and the exposed braided wire""s part on the insulating inner rind""s side are covered with the pair of half-box parts being deformed to their closing position, while the exposed braided wire is connected to the pair of press-fitting parts since they are press-fitted to the exposed braided wire.
With the above-mentioned structure, it is possible to complete the assembling of the shield terminal to the shield wire and improve the shielding capability of the coaxial connector without increasing the number of components and assembling steps. Additionally, with no increase in number of components and assembling steps, the manufacturing cost can be saved.
According to the second aspect of the invention, in the above-mentioned invention, the whole periphery of the inner housing is brought into contact with the opposing end faces on the side of respective front ends of the half-box parts being deformed to their closing position, while the whole periphery of the braided wire is brought into contact with the opposing end faces on the side of respective rear ends of the half-box parts being deformed to their closing position.
In this case, since the inner terminal and the exposed braided wire of the shield wire are covered with the pair of half-box parts of the shield terminal in general perfect, the shielding capability is further improved.
According to the third aspect of the invention, in the above-mentioned invention, the inner housing is provided, in the inner terminal accommodating part, with a flexible hook for engagement with the inner terminal.
In this case, owing to the provision of the flexible hook, the connection between the inner housing and the inner terminal is further strengthened.
According to the fourth aspect of the invention, in addition to the above constituents of the end structure, it may comprise an outer housing made of insulating material and having a terminal accommodating part formed for accommodating the shield terminal being assembled to the shield wire, wherein the shield terminal has a lower engagement claw formed on the bottom part for engagement with the outer housing and upper engagement claws formed on the half-box parts for engagement with the outer housing.
In this case, owing to the addition of the outer housing, the shielding capability of the coaxial connector is further improved. Furthermore, owing to the provision of the respective claws, the connection between the outer housing and the shield terminal is further strengthened.
According to the fifth aspect of the invention, the end structure may further comprise a spacer for locking the shield terminal accommodated in the outer housing, wherein the outer housing has a spacer insertion hole allowing the spacer to be inserted thereinto.
In this case, owing to the insertion of the spacer into the outer housing, the shield terminal is accommodated in the outer housing stably.
According to the sixth aspect of the present invention, there is also provided a method of treating an end of a coaxial connector, comprising the steps of:
preparing a shield wire consisting of a conductive core, an insulating inner rind covering the core, a conductive braided wire covering the insulating inner rind and an insulating outer rind covering the braided wire:
peeling the shield wire partially so as to expose the core, the insulating inner rind and the braided wire;
preparing an inner terminal and sequentially press-fitting the inner terminal to the exposed core for electrical connection;
preparing an inner housing made of insulating material, the inner housing having an inner terminal accommodating part formed for accommodating the inner terminal inserted thereinto;
preparing a shield terminal made of conductive metal, the shield terminal including:
a bottom part;
a pair of half-box parts formed to stand on both sides of the bottom part integrally and allow of plastic deformation due to press-fitting to their closing position where respective opposing end faces of the half-box parts butt each other; and
a pair of press-fitting parts formed to stand on both sides of the bottom part and also configured to be connectable with the exposed braided wire by the press-fitting parts press-fitting;
inserting the inner terminal into the inner housing through a rear opening thereof, thereby completing an inner housing assembly;
installing the inner housing assembly into the shield terminal through a clearance between the pair of half-box parts in their opening position;
press-fitting the insulating outer rind and the exposed braided wire of the shield wire to the press-fitting parts of the shield terminal by using a press-fitting machine; and simultaneously
press-fitting the pair of half-box parts in the opening position thereby to close them by using the press-fitting machine.
According to the above method, since the shield terminal closing process is carried out simultaneously with the crimping process to fit the braided wire under pressure and the crimping process to fit the insulating outer rind under pressure, the number of components and assembling steps is reduced, so that the assembling process can be executed effectively.
In this case, owing to the addition of the above steps, the shielding capability of the coaxial connector is further improved.
According to the eighth aspect of the invention, the above method further comprises the steps of:
preparing a spacer for locking the shield terminal accommodated in the outer housing; and
inserting the spacer into the outer housing, thereby locking the shield terminal in the outer housing.
In this case, owing to the addition of the above steps, the shield terminal is accommodated in the outer housing stably.
According to the ninth aspect of the invention, in the above method, the shield terminal has a lower engagement claw formed on the bottom part for engagement with the outer housing and upper engagement claws formed on the half-box parts for engagement with the outer housing.
In this case, owing to the provision of the respective claws, the connection between the outer housing and the shield terminal is further strengthened.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompany drawings.